At present, in the LTE system, seven kinds of transmission modes are defined, wherein each transmission mode adopts different multi-antenna processing methods, therefore different channel information needs to be fed hack. These seven transmission modes and the corresponding aperiodic channel quality information (CQI) feedback modes are as follows:
the transmission mode 1 (based on single antenna transmission mode of the antenna terminal port 0) adopts aperiodic CQI feedback mode 2-0 or 3-0;
the transmission mode 2 (transmit diversity) adopts aperiodic CQI feedback mode 2-0 or 3-0;
the transmission mode 3 (open loop multiplexing) adopts aperiodic CQI feedback mode 2-0 or 3-0;
the transmission mode 4 (closed loop multiplexing) adopts aperiodic CQI feedback modes 1-2, 2-2 or 3-1;
the transmission mode 5 (multiple-input and multiple-output (MIMO)) adopts aperiodic CQI feedback mode 3-1;
the transmission mode 6 (closed-loop multiplexing with rank of 1) adopts aperiodic CQI feedback modes 1-2, 2-2 or 3-1; and
the transmission mode 7 (based on single antenna transmission mode of antenna terminal port 5) adopts aperiodic CQI feedback mode 2-0 or 3-0.
The feedback contents of each aperiodic CQI feedback mode in the above are as shown in Table 1.
TABLE 1Feedback Contents of Each Aperiodic CQI Feedback ModeFeedbackmodesFeedback ContentsMode 1-2Full bandwidth (hereinafter referred to as wideband) feedback: optimum PMI (pre-coding information) of each subband, the Wideband CQI of each flow (the feedback PMI of each subband adopted), and only in the transmission mode 4, different feedback modes are adopted according to the different ranksMode 2-0User equipment (UE) selects subband feedback, UE selects M subbands, reports the CQI of the M subbands of the first flow, and reports the wideband CQI of the first flow. For the transmission mode 3, the CQI is calculated according to the reported RI, and for other modes, the rank equals to 1Mode 2-2UE selects subband feedback, and reports the CQI of M subbands (using one PMI), the PMI of the M subbands, wideband CQI and wideband PMI (only in the transmission mode 4, different modes are adopted according to the different ranks)Mode 3-0high level configured wideband CQI (which is sent only on the subband set), and the CQI of each subband (which is sent only on the subband) aims at the first flow (only in the transmission mode 3, different feedback modes areadopted according to different ranks)Mode 3-1High level configured subband feedback, wideband PMI, subband CQI of each flow (using wideband PMI). wideband CQI of each flow (using wideband PMI). For antenna mode 4, the corresponding PMI and CQI are calculated according to the RI, and for other modes, the rank equals to 1
While, the transmission mode corresponding to the forming of dual flow beam has not be designed in the standard, and the aperiodic CQI feedback mode which can be able to support the forming of dual flow beam also has not been determined. In the present invention, the corresponding transmission mode and the aperiodic CQI feedback mode will be designed as for the forming of dual flow beam.